Process for producing acetic esters of butenediol

ABSTRACT

Acetic esters of butenediol are prepared by the reaction of butadiene, an oxygen containing gas and acetic acid in the presence of a catalytic amount of a catalyst system of at least one member being cupric bromide (II) and/or cupric acetate (II), and at least one member being an alkali or alkaline earth metal salt acetate and/or bromide.

United States Patent 1 [111 3,723,510

Ono et al. 1 Mar. 27, 1973 PROCESS'F OR PRODUCING ACETIC [56] ReferencesCited ESTERS OF BUTENEDIOL Inventors: Isao Ono; Tadahisa Yanagihara;Hiroaki Okada; Takeshi Uotani, all

of Shin-Nanyo, Japan Assignee: Toyo Soda Manufacturing Co., Ltd.,Oaza-Tonda, Shin Nanyo-shi, Yamaguchi, Japan Filed: Dec. 9, 1971 Appl.No.: 206,539

Foreign Application Priority Data Dec. 14, 1970 Japan ..45/l 10550 us.Cl. ..260/497 R Int. Cl ..C07c 67/04 Field of Search ..260/497 R FOREIGNPATENTS OR APPLICATIONS 4,531,926 lO/l970 Japan ..260/497 R PrimaryExaminerHenry R. Jiles Assistant ExaminerRichard D. Kelly Attomey--Norman F. Oblon et al.

[ ABSTRACT 8 Claims, No Drawings PROCESS FOR PRODUCING ACETIC ESTERS OFBUTENEDIOL BACKGROUND THE INVENTION 1. Field of the Invention.

This invention relates to a one-stage process for producing aceticesters of butenediol from butadiene.

2. Description of Prior Art The acetic esters of butenediol, such as2-butene- 1,4-dioldiacetate (also known as 1,4-diacetoxy-2-butene),3-butene-l,2-diol diacetate (also known as 3,4- diacetoxy-Lbutene) and3-butene-l,2-diol monoacetate, are useful for many diverse applicationsincluding the synthesis of butenediol and tetrahydrofuran, etc.

It has been disclosed that butenediol diacetate can be prepared in aone-step process by the reaction of butadiene and acetic acid in thepresence of cupric chloride (ID-sodium acetate (Japanese PatentPublication No. 3 1926/ 1970).

This process, as well as all of the other conventional techniques forproducing butenediol diacetate, have suffered the disadvantages that:

1. They were based on a quantitative reaction and not on a catalyticreaction;

2. their reaction rate and yields were quite low, and

3. the separation of the reaction product was difficult due to the smallweight ratio between the reaction product and the catalyst. I

A need exists, therefore, for a process of producing butenedioldiacetate by a catalytic reaction wherein the rate of reaction andproduct yields are high and wherein the reaction product can be easilyseparated from the reaction mixture, which would thereby be quiteindustrially attractive.

SUMMARY OF THE INVENTION Accordingly, it is one object of this inventionto provide a process for producing acetic esters of butenediol by a highyield, high reaction rate catalytic reaction.

This and other objects, as will hereinafter become more readilyapparent, has been attained by reacting in a single stage, butadiene, anoxygen containing gas and acetic acid in the presence of a catalyticamount of a catalyst system of cupric bromide (H) and/or cupric acetate(II), and the acetate and/or bromide of an alkali metal and/or analkaline earth metal, wherein at least one of the components in saidcatalyst system is the bromide.

DETAILED DESCRIPTION OF THE INVENTION Although the quantity of cupricbromide (II) and cupric acetate (II) used in the process of thisinvention is not particularly critical, it is desirable to use 0.02 2.0=mol/l., and preferably 0.2 1.0 mol/l. in the reaction liquor.Similarly, although there is no particular criticality in the quantityof alkali metal or alkaline earth metal acetate and/or bromide used, itis desirable to use 0. l to equivalent weights/equivalent weight ofcupric salt, and more preferably 0.5 5 equivalent weight/equivalentweight.

Instead of using a metalacetate directly, it is possible to use acompound, such as an hydroxide, which, under the reaction conditions,will form the corresponding acetate. 1

The oxygen containing gas used herein may be pure oxygen, or oxygendiluted with an inert gas, such as nitrogen, and hence air may be used.

The temperature of the reaction should be maintained within the range ofroom temperature to 200 C. and preferably 50 to 150 C. with the pressurebeing at least atmospheric or higher. The particular reactiontemperature and pressure will depend upon the particular productdesired. For instance, the quantity of monoacetate will tend to be lowerand the quantity of diacetate will tend to be higher with an increase inthe reaction temperature.

Using the methods of this invention, acetic esters of butenediol can beprepared by a reaction which is characterized by a high reaction rateand a high yield as compared with prior state of the art methods.

Moreover, the reaction of this invention is quite industriallyattractive, since it is a catalytic reaction.

Having now generally described the invention, a further understandingcan be attained by reference to certain specific Examples which areprovided herein for purposes of illustration only and should not beconstrued as limiting unless otherwise so specified.

EXAMPLE 1 200 mls. of glacial acetic acid, 20 g. (0.5 mol/l) of cupricacetate (II), and 42 g. (2.0 mol/l) of lithium bromide were placed in areaction vessel equipped with a thermometer, a cooler, a gas blowingtube and a stirrer. The temperature was maintained at C. in an oil bath,and a mixed gas of butadiene and oxygen, in a ratio of l l, was blowninto said autoclave at a rate of 12 liters per hour and the reaction wascontinued for 20 hours, while stirring.

EXAMPLES 2 13 The following experiments were carried out using similarequipment and procedures as in Example 1, ex-

COMPARATIVE EXAMPLES l 2 The following experiments were conducted usingsimilar equipment and procedures as in Example 1, but carrying out thereaction using certain well known catalysts. The results are shown inTable I.

EXAMPLE i4 100 mls. of acetic acid, 5.6 g. (0.25 mole/l) of cupricbromide (II), 2.05 g. (0.25 mol/]) of sodium acetate and 10.8 g. ofbutadiene were placed in an autoclave of 20 cc. capacity, the inside ofwhich was lined with teflon. A mixed gas of oxygen and nitrogen, in aratio of 1 l, was blown into said autoclave under a pressure of up to 20kglcm The reaction was then carried out at C. for 3 hours. Oxygen wasreplenished by using a secondary pressure accumulator. The results ofanalysis of the product by gas chromatography showed the formation of3-butene-1,2-dioldiacetate, 3-butene-l,2- diolmonoacetate and 2-butene-l,4-dioldiacetate in amounts of 4.6 g., 2.0 g., and 8.4 g., respectively.

TABLE 1 ("italysts (IIlOlP/l.) Reaction condition lroduct q Alkali orAlk ahne earth 'Iom p. W 6 Tom Example Cupric salt metal salt Hour/w. A4 132 4 Cupric acetate 0.5... Lithium bromide 2.0 l :JO :4: 93: 0 1 u doSodium bromide 2.0.. )0 50 6. 0 m. 9 3 8 7 thor Potassium bromide 2. 9,320 14:7 43:4 11.4 69-5 Magnesium bromme 1 0 b0 20 10. 9 16. s 10.0 31. 7

90 20 17. 2 46. 1 10.8 74. 70 '20 7. 2 44. 0 10.0 61.5 110 5 6.2 2.1 11.4 19.1 90 5 3. 3 12.0 3. 8 19.1 0 110 5 6. 9 11. 5 'ii I'sbliimiiiirriiilie 0.5. 90 3 6%, 1 74: 9 dupriehrornide 2.0 Sodium acetate 2.0 206.0 12.1 1' 5 19.6

. Cupric bromide 0.2 do

Comparison 2O 0. 5 1. 3 0. 4 2. l 1 Cupgic chloride 0.5.. Sodiagnacetate 0.5 20 3. 1 1. 0 2 4 6 5 o v v n C =2-buteuo-1,4

A =3-butene-l,l-dioldiacetate (=3,4-diacctoxy-l-butcne); B=3-butene-1,2-dlolmonoacetato;

I dioldiacetate (=1,4-diacetoxy-2-butene).

Having now fully described the invention, it will be 20 apparent to oneof ordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit or scope of theinvention. Accordingly,

What is claimed as new and desired to be secured by letters patent is:

l. A process for producing acetic ester of butenediol which comprisesreacting butadiene, an oxygen containing gas and acetic acid in thepresence of a catalytic amount of a catalyst system consistingessentially of at least one member selected from the group consisting ofcupric bromide (11) and cupric acetate (11) and at least one memberselected from the group consisting of the acetate and bromide of analkali metal and an alkaline earth metal, wherein at least one componentof said catalyst system is the bromide.

2. The process according to claim 1, wherein the alkali metal islithium, sodium or potassium.

3. The process according to claim 1, wherein the alkaline earth metal isbarium, magnesium or calcium.

4. The process according to claim 1, wherein the quantity of cupric saltis in the range of 0.02 to 2.0 moles per liter of reaction liquor.

5. The process according to claim 1, wherein the quantity of the alkalior alkaline earth metal compound is 0.1 to 10 weight equivalents perweight equivalent of cupric salt.

6. The process according to claim 1, wherein the reaction temperature isfrom room temperature to 200 C.

2. The process according to claim 1, wherein the alkali metal islithium, sodium or potassium.
 3. The process according to claim 1,wherein the alkaline earth metal is barium, magnesium or calcium.
 4. Theprocess according to claim 1, wherein the quantity of cupric salt is inthe range of 0.02 to 2.0 moles per liter of reaction liquor.
 5. Theprocess according to claim 1, wherein the quantity of the alkali oralkaline earth metal compound is 0.1 to 10 weight equivalents per weightequivalent of cupric salt.
 6. The process according to claim 1, whereinthe reaction temperature is from room temperature to 200* C.
 7. Theprocess according to claim 1, wherein the pressure is at leastatmospheric.
 8. The process according to claim 1, wherein the oxygencontaining gas is air.